Pump and motor



sheets-sheet 1 i E. BNEDEK PUMP AND MOTOR Filed Oct. 18, 1935 www EL EKBE/VLSDEK.

Sept. 16, 1941.

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Sept. 16, 1941. E. BENEDEK lPUMPl AND MOTOR vFiled oct. 18, 1933 3Sheets-Sheet 2 EL 5K BE/vfog/f.

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Sept. 16, 1941. E, BENEDEK 2,255,962

PUMP AND MOTOR Filed oct. 18, 1935 3 shets-sheet s Gum;

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. sible the elimination of Patented Sept. 16, 1941 UNITED STATES PATENT.OFFICE PUMP AND MOTOR Elek Benedek, Mount Gilead, Ohio ApplicationOctober 18, 1933, Serial No. 694,179

3 Claims.

This invention relates to high speed, high pressure, rotary pumps of theradial piston type.

Pumps of the type referred to ordinarily comprise a driven cylindervbarrel rotatable about a iixed axis and carrying a radial series ofpistons disposed about said axis and reciprocable radially thereto. Asheretofore designed, commercial forms of pumps of the character men--tioned also include a stroke-controlling drum,

surrounding said driven barrel, and provided with a pair of axiallyspaced circular grooveways.l

controlling drum, being supported by adjustablel bearing members, isrshiftable to carry the eccentricity of said rotational axis and tothereby vary the stroke of the pistons. Such -constructionnecessitates'heavy sliding slippers to carry the high pressure pistonload on the sliding cooperating circular grooveways of said strokecontrolling drum on oil film, tion or seizure between the reactionsurfaces of the drum and the sliding surfaces of the slippers, and alsounduly long radial guiding surfaces for the pistons to take up the greatreciprocating without excessive ricmass forces of the slippers withoutundue fric- The driven cylinder barrel of such construction is directlyandI rigidly coupled with the driveshaft, without any flexibility andtorque transmitting bearing means, which would relieve said barrel fromundue strains caused by the driving torque and misalignment of theshaft.

One object vof the present invention is the provision of a designed asto make possible the elimination lof the bearing sliding slippers of thepistons above referred to, and substantially reduce the `acceleratingmass forces on the pistons which tend to wear out same, by substitutingfor them anti-friction devices which have a mass of about y ten timesless that of the above .mentioned slippers.

pump of the type mentioned, so'

Another object is the provision of a pump of the type mentioned sodesigned as to make posa heavy stroke-controlling drum. and substitutefor it apair of antifriction innerbearing rings which have a mass ofmany times less that of aforesaid heavy drum, with much less inertia,and more accessible for high grade finish and assembly and disassemblywithout disturbing any other parts of the pump assembly.

A further object is the provision in a pump of the type mentioned ofnovel means for sustaining the piston reactions in such a manner as toeliminate all sliding friction between the coacting parts of the pumpand dispense with a centrifugal iluid pressure reservoir, whichheretofore Was necessary to provide lubrication for said slidingmembers.

A still further object is the provision of novel means for the operationof the pistons during A suction stroke, which not only will add-to theeiiiciency of the pump, but will provide and facilitate the axialassembly and disassembly of the rollersland roller tracks.

Another object is the provision of a pump of .l the type mentioned, sodesigned that the cylinmally aligned and coaxial with said cylinder"barrel, to take up the bearing reaction and misalignments of the drivingshaft and torque respectively.

Other more specific objects and advantages will appear from thefollowing description of an illustrative embodiment of the presentinvention:

In the accompanying drawings:

Fig. 1 is an axial constructed in accordance with the present invention.

Fig. 2 is a transverse sectional view on the -line 2-2 of Fig. 1.

Fig. 3 is a transverse sectional view on line -3-3 of Fig. 1. y l Fig. 4is a diagram showing the simultaneously rotating two .centerlines of theroller track and cylinder barrel respectively at the moment, when 55both centerlines depart from their dead center vsectional view of apump.

` tion 30 of central cylindrical valve 29 is pressed under heavyhydraulic pressure, to form for pump mains 35 and 36a leak-proof and anair-proof hydraulic connection. The proper relative position of valve 29during the press fit operation is assured by key 55. 'I'he main pumpports 3I and 32 are in the main meridian plane of all the pistons 40 andcommunicate with the piston cylinders 39 through slightly reduced radialopenings as at 56. and 34 form communicating passages between theinternal pump port 3| and external main pump port 35, and the other pairof axially parallel holes 331 and 341 form communication between theother set of internal and external ports 32 and 36. respectively. Eachside of the internal ports 3| and 32 there is a 'pressure film spreadlimiting groove as at 31 and 38; to limit the unbalanced hydraulicpressure exerted on the side of the prefssure internal pump port at atime.

Drive shaft I 3, supported in appropriate antifriction bearing I1 in endplate I2, projects into the casing and is keyed or otherwise fixed atits inner end todriving head I9. The end shoulder 24 of its inner end isrigidly secured against axial displacement by set collar I5,uponthreaded portion I4 in a well known manner. `Drive shaft; I3 has ahollow portion as at I6 to receive a concentrically disposed and reducedportion 23 of cen- One pair of parallel axial holes 33` medium of thebearings 48 and outer races 41.

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trai valve 29, projecting in said hollow portion I6, and rotativelymounted on tiny needle rollers 2| which are engaged in recess 22 ofshaft end 23.

Driving head I9 is provided with an appropriate cylindrical shoulder toreceive the inner race of bearingmeans I8, Whereas the outer race ofbearing means fits in corresponding internal groove provided in endplate I2. The bearing I8 locked in position by sleeve 53 and set screwsDriving head I9 is provided with a plurality of coupling elements as at20, to engage similar coupling elements of the driven cylinder barrel28. In this manner, there .is provision for suflicient flexibilitybetween barrel and driving means to assure free rotation of the barrelon'its supportl ing bearing means 26 and 21.

Cylinder barrel 28 comprises a substantially cylindrical bodyincorporating sufficient weight 3 to exert a. predetermined flywheeleffect. and

thereby -to assume smooth and vibrationless operation of the=pump.'I'his barrel 28 is provided 1 with concentric counterbores at both endsto receive anti-friction bearing means 26 and 2,1. In

addition to the central cylindrical portion, barrel 1 28 has a circularflange portion as at 51 to provide adequate `guide surfaces for theenlarged outer ends of the radial pistons as at 55. I

`Each enlarged outer end of the pistons is pro- .vided with a pair oflateral journals or crosspins 1 42 and 43 which carry rollers 45,mounted on i needle roller bearings 44. Each of the crossheadv I rollers45 is supported in both radially in and out direction by appropriateindependent annular reactance members or oating rings 45 and 49respectively, 46 of which is the external reactance member'which alsoforms the internal race of a Eccentric reactance housing is attached tocontrol rods 5| and 52 which lead to control apparatus not shown in thedrawings and which will operate the stroke-controlling bearing housingl5I) to change the stroke and the deliveryof the pump.

Pintle or central valve 29 being supported now in its ends itsdeflection under resultant hydraulic piston load will be only afractional part of the deection inherent in pumps of prior designutilizing the cantilever type of pintle.

The pintle cutouts 3| have a shape of continuously increasing ordecreasing passage area for the influx or eiux of the fluid to and fromthe cylinders and which area is strictly proportional Ito the momentarydisplacement of the individual pistons. Limiting oil lgrooves 31 and 38are provided in the coactingsurfaces of the barrel 28 grooves 31 and 38.Therefore it will be seen that, due to the axial extension of thepressure or film' at both sides of the limiting grooves, not

-only the total axial spread of the lm' will be limited' but a certainamount of hydrostatic load created by the lm spread will be balanced.The partial balance of the hydrostatic load between the pintle andcylinder barrel will naturally reduce the radial load of bearings 26 and21. A

perfect balance of the pintle 29 is impossible due to the operatingclearance between the pintle and cylinder barrel which always requires acertain amount of hydro-dynamical unbalance even if there is asubstantial lhydrostatic balance. For this reason it is of primaryimportance to vprovide pilot needle bearings 2| in the counterboredenlarged end 24 of shaft I3 which is located substantially in the planeof the driving head bearing y I8 and thereby the deflection of thelpintle end stub 23 will be indirectly placed and taken up by the heavybearing I8.

In order to reduce the reciprocating mass forces or inertia. of thecross head devices, I reduce not only the masses of said devices butalso their weight by making the rollers 45 from light and wear resistantmaterial, such as duralu-I mmum.

In order to compensate for the decrease of momentum of the entire pumpassembly caused by the reduction of wheel masses 45, I make the cylinderbarrel extra-heavy, to exert a positive A complete set of anti-frictionbearings 48. An adamount of rotary momentum required and predeterminedby the speed and size of the pump, to give a predetermined degree ofevennes's or smoothness to its running.

The extra heavy and substantially cylindrical f barrel 28 thus willpermit mounting the' bearings 28 and 21 directly between pintleandbarrel thus to assure and maintain an accurate concentricity.

and a permanent oil film in the concentric clearance space between themthrough this type of mounting.

It is further noticeable that owing to the provision of the exibleconnection as at 20, in the form of a pair of normally aligned teeth orjaw coupling, there isno unbalanced or side load applied on the cylinderbarrel as it is the case when the pump drive is not coaxial with theaxis of the pintle, but it is parallel and eccentric thereto. Hence, thegreat significance of the pilot support of the outer end 23 of pintle 29because it facilitates the balanced drive of the cylinder barrel andcentered mounting thereof. directly on the pintle.

Since the mechanical mass of needle' rollers 44 is very small andpractically negligible as to building up inertia forces, and furthermoresince the mass of wheels 45 is a fractional part only of masses of priorconstructions in pumps of the type referred to, it is obvious that in mydesign the inertia mass of needles 44 and rollers 45 may be less thanthe inertia of the pin of old designs. in view of the fact that I makemy Wheels 45 from light weight metal such as duraluminum, which can behardened. Consequently, it is possible in my new pump that the totalinertia of the Wheels is negligible compared to the inertia of the largesliding shoes and slippers of old designs, wherein the friction drag isanother big-factor which adds to the inertia, whereas in myanti-friction devices such friction drag is entirely eliminated.

It must be remarked that one incident importance of the pilot supportingof pintle 29 is in the fact that by set collar 25 bearings 26 and -21may be pre-loaded or adjusted and thus the cylinder barrel will have adefinite set axially irrespective of the pressure; since pintle 29 andpintle bore have a slight taper fit, which fit exerts an axial forcecomponent especially under high pressure. By the expression definiteset, above mentioned, it is intended to. define that by a certain axialadjustment of the inner race of the bearing 26 by means ofthe ,setcollar 25, the latter is adaptedv to act against the bearing 21 and thepintle shoulder 58, and thus the axial load component of the pressurefluid on the cylinder barrel and against the tapered pintle will nothave any effect to slightly shift the barrel oi the pintle. Therefore,due to the capability of preloading or pre-adjusting the bearing 26, thecylinder barrel will maintain a'predetermined radial clearance withreference to the pintle which would not otherwise be obtainable,especially where the action of the pressure 'fluid is such as to shiftthe cylinder barrel in the opposite direction. In 'all of the olderdesigns a positive setting of the cylinder barrel is impossible, sincethe bearing which would correspond to 426 is mounted ordinarily inendcover l2, hence an accuracy in the axial 'position of the cylinderbarrel is impossible, since the body portion of the pump usually expandsand loosens the bearing mounted in the end cover.

Referring more specifically to the bearings 26 and 21, the bearing 21has an inner race press fitted onto the pintle. heavy pintle portion atthe zone of the bearings 21, which is immediately adjacent the portionIt will be seen that theV ofthe pintle supported in the casing, thatlittle deflection can occur and with the barrel and pintle carefullyformed for concentricity'this concentricity will be maintained, theclearance on such bearing being less considerably than the f clearancespace between the pintle and barrel.

Due to the great rigidity of the pintle at this portion this vcenteringyof the pintle and barrel will be maintained. At the opposite end of thepintle,

of wheel 45 on member 46 the acceleration force.

however, the maximum Vdeflection occurs and it is because of thisdeflection that trouble is` apt to arise. The bearing 21 is actually apivotal point with respect to the barrel andpintle about which wheels.

relative swinging of the two with respect to each other occurs, due todeflection of the pintle under load, machining inaccuracies of thepintle and barrel, assembly inaccuracies or warpage. The result of suchrelative pivoting about the bearings 21, however, fmagnifies thedeflection and misalignment at the opposite end of the pintle.`

but necessarily is preloaded axially when thebearing 26 is preloaded bytightening of the nut 25. Thus the bearing 21 acts as an abutment forholding the cylinder barrel against axial movement so that the ballbearing 26 may be preloaded both axially and radially.

To accommodate such axial adjustment, preloading or setting of barrel29,' race tracks 46 are made so that they yield axially to such extentas necessitated by the adjustment of nut 25, lthus the assembly will befree and unstrained, even if cylinder barrel 28 is vaxially adjusted andsetagainst shoulder 56 of pintle head 30.

The suction stroke of allpistons is controlled by internal annularvreactance members or floating rings 49. Their significance is nowobvious when we consider wheels 45 pushed with tremendous force, exertedby crosshead pins 42 and 43, against the external reactance members 46,rotating with the Speed of driveshaft I3, have to carry out swingingmotion only and not complete revolutions. Therefore, in orderV to makethis swinging motion possible the floating rings or internal reactancemembers 49 swings back and forth with the wheels so as to eliminatesliding of the Wheels and the sliding friction inherent in position asshown in Fig. 3, will have incomplete 'rotary motion only, the amount ofwhich is determined by the eccentricity of the axis of barrel 28 vandthe axis of reactance housing 50.

In Fig. 4, axis 64 designates the dead center position of all thepistons, so that wheel 45 when on axis 64, carries the piston `in itsneutral position. In this neutral position which coincides with thecenter line of rods 5I and 52 in Fig. 1 the momentary centerlines 6I and62 of the barrel 28\and of the races v46 will also coincide. 'But aftera rotation with an angle of a, centerlines 6l and 62 will-be separatedat a. distance'marked 63. Since the rotation is athigh speed and thetime element is too short to effect such relative shift required toeffect this shift may-become enormous. According to myv analysis, theabsolute l value of such acceleration is directly proportional to thesquare of the angular velocity of the pump and is in linear proportionto the mass of the Since in high speed pumpsl the speed mustbemaintai'ned' as a commercial requirement` in order to reducetangential acceleration forces on the pistons it is necessary to reducethe masses of the rollers 45, which has been done.

The pump will operate in a well-known manner. When stroke controllinghousing 50 is in l concentric relation with cylinder barrel 29 as it isshown in Figs. 1 and 2, the pistons will be operated between concentricfloating rings `46 and 49 which are further concentric with the vaxis ofthe cylinder barrel 28 as well as of pintle 29, therefore there will beno pumping action in the l cylinders 39.

However, when the stroke controlling' or reactance housing 50 and thecooperating members 46 and 49 will rbe shifted into eccentric positionon coopera-tive pads 59 and 60, as shown in Fig. 3, the pistons 40.assume relative reciprocation in their associated cylinders 39 to theamount of twice the momentary eccentricity of the shift.

By shifting thehousing 50 into the opposite direction the pump willreverse its discharge in a well known manner. It will thus be noted thatI have provided a pump of simple and economical design, in which,besides the hydraulic instrumentalities such as pistons, cylinders andvalve,V lthere is no frictional element involved to create heat underthe heavy load, therefore the Working temperature of my pump will belower than thatof pumps previously referred to and will withstand heavyduty service for long periods of time -without excessive wear andseizure.

Various changes may be made in the embodiment of the present inventionhereinabove speciflcally described without departing from the inventionas dened in the appended claims.

I claim:

1. In a rotaryradial piston pump or motor of the character describedhaving a valve pintle supported at one end, a piston carrying barrelrotatably mounted on the pintle and in valving cooperation therewith,and said pintle having a tion with respect to the head and for resistingdeection of the pintle, means flexibly connectin g the driving head andbarrel, and impeller -means carried by said driving head.

2.l In a rotary radial piston pump or motor of the character describedhaving a casing, arotatable piston carrying barrel therein, a taperedvalve pintle fixedly mounted at one end in the free end portionprotruding beyond the barrel at f the end opposite the pintle support, adriving head separate from the barrel, means independent of the pintleand barrel for rotatably supporting the head and for constraining thehead from radial and axial loading of the barrel by the driving head,said driving head having an axial bore. coaxial with the pintle andopening theretoward tle, pilot bearing means for supporting theprotruding pintle end in said bore for relative rota- .and receiving thesaid protruding end of the pincasing and in valving relation in thebarrel, and antifriction bearing means between each end of the barreland the pintle rotatably supporting the barrel on and invalvingjrelation .to the pintle, a rotatable driving head coaxial withthe barrel adjacent the opposite end of the pintle, an impeller shaftoperatively connected to said head, means disassociated from the pintle,the shaft, and the barrel for rotatably mounting said head on the casingand maintaining said head in xed position axially and radially relativeto thepintle, clutch means connecting the barrel and head for rotationtogether and for maintaining said con-l nection while permitting limitedrelative radial and axial movement of vthe vhead and barrel, whereby thebarrel is relieved from radial and axial loadingv by the head-while thedriving relation between the head and -barrel is maintained.

3. In a rotary radial piston pump or motor of the character described, acasing, a valve pintle xedly secured by one of its ends in the casing,

a piston `carrying barrel coaxial with the pintle,

reactance means, piston and cylinder assemblies operatively interposedbetween the barrel and reactance means, sets of anti-friction bearingsmounting the pintle and respective end portions of the barrel forrotatably supporting the barrel on the pintle and for constraining thebarrel and pintle to accurate coaxial relation with respect to eachother, a self-contained driving head separate from and coaxial with thebarrel and'pintle,

vvan impeller shaft operatively connected to said

